Liquid nitrogen enabler

ABSTRACT

A method and apparatus for using liquid nitrogen to render fires and explosives inert, thus extinguishing and controlling the fire or explosive. The present invention utilizes a trough comprising a plurality of apertures to rain liquid nitrogen down on an area underneath the trough so as to evaporate the liquid nitrogen, super cool the surrounding area, and remove oxygen so as to render the area inert.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of Ser. No. 10/437,538, filed May 14, 2003, and entitled “Liquid Nitrogen Enabler.”

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a method of applying liquid nitrogen to a fire and, more particularly, relates to a method of applying liquid nitrogen to a fire so as to maximize the generation of gaseous nitrogen to provide for a greater cooling effect.

2. Discussion of the Related Art

Conventional means for using liquid nitrogen to extinguish a fire, such as that disclosed in U.S. Pat. No. 6,666,278 to Cicanese (hereinafter “the Cicanese patent” or “Cicanese”), have used the release of liquid nitrogen into a fire column to facilitate the introduction of nitrogen gas into the fire. The mechanism disclosed in Cicanese, however, is limited to the application of oil well fires, and furthermore, the Cicanese patent does not disclose a method to cause mass evaporation of liquid nitrogen in the fire.

Similarly, U.S. Pat. No. 5,327,732 to DeAlmeida (hereinafter “the DeAlmeida patent” or “DeAlmida”) discloses an apparatus for extinguishing fires using nitrogen. DeAlmeida, however, relates to a high capacity movable plant that continuously distributes nitrogen in a gaseous or in a mixture of gaseous and liquid phases. However, the DeAlmeida patent does not provide a simple, yet effective means of delivering nitrogen in a timely manner.

U.S. Pat. No. 6,401,830 to Romanoff (hereinafter “the Romanoff patent” or “Romanoff”) discloses a process for extinguishing a fire using an inert gas as the fire-extinguishing agent. However, the Romanoff patent fails to disclose an effective means of delivering liquid nitrogen to the fire.

U.S. Pat. No. 5,197,548 to Volker (hereinafter “the Volker patent” or “Volker”) discloses a method of controlling a fire through the spraying of liquid nitrogen onto the fire. Delivering liquid nitrogen in the method proposed in Volker, however, may leave glowing embers capable of re-igniting the fire.

The need therefore has arisen to provide a simple, effective, method of separating liquid nitrogen into small droplets so as to cause mass evaporation in a fire draft such that extraneous gases, other than the evaporant, are prevented from entering the fire.

The need has additionally arisen to provide a method of applying liquid nitrogen to a fire such that the fire is not susceptible to re-ignition. Furthermore, a need has arisen to provide a method with a simple, yet effective delivery means such that the method may be employed quickly in the area of a fire.

Additionally, the need has arisen to provide a safe and effective method of rendering land mines inert so that they may be safely transported to a detonation chamber.

SUMMARY OF THE INVENTION

In accordance with one aspect of the invention, a method of using liquid nitrogen to control and extinguish a fire by dispensing liquid nitrogen as substantially small droplets and applying it to a fire so that the fire is substantially consumed by the liquid nitrogen so as to rob the fire of oxygen.

In another aspect of the present invention, a method of extinguishing and stopping the travel of a wild fire with a directional travel is disclosed through the assembling of a trough or pipe at a direction ahead of the travel of the fire, wherein liquid nitrogen is supplied in the trough or pipe so as to extinguish and stop the travel of the fire.

In another aspect of the present invention, a method of extinguishing and controlling a fire contained in a tall structure such as a skyscraper and the like is provided wherein a trough carrying liquid nitrogen is employed through an opening in the structure so as to apply the liquid nitrogen directly to the fire.

In accordance with another aspect of the present invention, a method of freezing a land mine using liquid nitrogen such that the mine is rendered inert and may be safely transported to a detonation chamber nearby.

In yet another aspect of the present invention, a method of using liquid nitrogen to freeze and safely remove explosives, in particular, buried explosives is disclosed.

These and other advantages and features of the invention will become apparent to those skilled in the art from the detailed description and the accompanying drawings. It should be understood, however, that the detailed description and accompanying drawings, while indicating preferred embodiments of the present invention, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred exemplary embodiments of the invention are illustrated in the accompanying drawings in which like reference numerals represent like parts throughout, and in which:

FIG. 1 a is a side cross-sectional view of the trough of one embodiment of the present invention;

FIG. 1 b is a top plan view of the trough illustrated in FIG. 1 a;

FIG. 1 c is a side view of the trough illustrated in FIGS. 1 a-b;

FIG. 2 is a perspective view of the nozzle design for one embodiment of the present invention;

FIG. 3 is a side elevation view of one embodiment of the trough design of the present invention;

FIG. 3 a is a schematic illustration of how to optimize the trough height illustrated in FIG. 3;

FIG. 4 is a side perspective view of one embodiment of the present invention;

FIG. 5 is a side perspective view of one embodiment of the present invention;

FIG. 6 is a schematic illustration of another embodiment of the invention illustrated in FIG. 5.

FIGS. 7 a-d are schematic views of a circular trough design in accordance with a second embodiment of the present invention;

FIGS. 8 a-d are schematic representations of another aspect of the trough design illustrated in FIG. 6;

FIGS. 9 a-d are schematic representations of another aspect of the trough design;

FIG. 10 is a schematic representation of another aspect of the trough design illustrated in FIGS. 8 a-d;

FIG. 11 is a schematic representation of a third embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

1. A First Embodiment of the Present Invention

Turning now to the drawings and initially to FIGS. 1-3, a method of applying liquid nitrogen to a region using a galvanized material forming a circle around the fire region is shown. A gutter or trough 10 having a plurality of holes or apertures 12 thereon is provided. The holes 12 are provided so that upon introduction of the liquid nitrogen into the trough 10, the liquid nitrogen flows to fill the trough 10 and leaks out of the holes 12 under the force of gravity, thus generating an area of “raining” liquid nitrogen on the surface below. The application of liquid nitrogen in this manner will generate a substantially gaseous application of nitrogen, thus resulting in a substantial volume of inert nitrogen gas cooling the air and the surrounding surfaces.

Turning now to FIGS. 1 a-c, an exemplary illustration of a trough design is shown. The trough comprises a plurality of spikes 16 on the underside of the trough 10 that are used to puncture the surface 14 below the trough 10 and to serve as supports for the trough 10. The trough 10 is positioned at a height above the surface 14 such that the entire fire draft is filled with evaporated, gaseous liquid nitrogen. This evaporation of falling droplets floods the fire air input making it only inert, non-flammable gas. The trough 10 is generally shaped as a gutter having end edges 18 that are substantially strong enough to retain its shape during use thereof. The holes 12 provided in the surface of the gutter are provided to optimize the droplet size of the liquid nitrogen so it evaporates completely as it reaches the surface 14.

In one aspect of the present invention, the trough is leveled such that the end 18 where the liquid nitrogen is introduced elevated with respect to the rest of the trough 10, thus using the force of gravity to aid in the flowing of liquid nitrogen through the trough 10. The slope of the trough 10 is gradual enough to both rain liquid nitrogen through the holes and to allow the liquid nitrogen to effectively flow through the entirety of the trough 10.

FIG. 2 shows another embodiment of the present invention wherein a dewar 20 is provided having a T-shaped outlet 22 to facilitate the pouring of liquid nitrogen two separate directions simultaneously into a circular or bi-directional trough arrangement. This particular embodiment allows for liquid nitrogen to be poured in two different directions in the case of a circular trough 10 arrangement. This particular arrangement may be most effective where the trough is being used to contain a centralized fire or along the length of a fire approached from a central point.

Turning now to FIGS. 3 and 3 a, a circular trough 10 configuration is shown wherein a fire is encircled, contained therein. As before, a central dewar 20 pours liquid nitrogen into the trough 10 flowing from an area of comparatively higher elevation down to areas of lower elevation. The introduced liquid nitrogen, under the force of gravity, rains down on the surface 14 below the trough 10. As the fire exhausts heated air upward, the cool air near the ground is drawn into the fire. Thus, as the liquid nitrogen is rained down on the surface 14 in the path of the fire draft, the cool oxygen filled air near the ground is held from the fire by the influx of inert nitrogen gas. FIG. 3 a shows the wind input draft 24 of the fire and the corresponding height limit 26, which can be determined through the utilization of a wind pole 32 with light weight fabric stripes tied to it that are configured to blow in the wind. The strips 28 above the draft height will remain limp, whereas those below the draft will extend in the general direction of the wind flow. Thus, the break height between the strips 28 defines the draft indicating the optimum height 30 of the stakes 16 for positioning of the trough 10. Thus, the flow of liquid nitrogen and subsequent raining thereof towards the surface 14 below supercools the space and floods the fire draft with nitrogen gas at a rate faster than it can be drawn into the fire. This disrupts the fire limiting the needed oxygen and cooling the substance burning below flash point. This flooding of liquid nitrogen into the fire space ends the burn, counters infernos and limits the smoke and soot spewed from the fire location.

This embodiment of the present invention may be used to control and extinguish wild fires having a directional travel. For example, a trough 10 may be quickly assembled and deployed at a location ahead of the fire's direction of travel. Upon approach of the fire, the liquid nitrogen is then dispensed to the troughs 10 so as to supercool the area ahead of the fire and populate the fire draft with the inert gas. As the liquid nitrogen converts to gaseous nitrogen, the nitrogen is sucked into the fire and the nitrogen effectively starves the fire of oxygen, thus extinguishing the bum. Any remaining embers may be safely treated to prevent re-ignition of the fire. As the nitrogen gas enters the fire, if further expands as it is heated and rises pulling more nitrogen gas into the fire, further cooling the area making it difficult for the fire to sustain its burning. Due to nitrogen's expansion during evaporation, it blocks the oxygen intake to the fire. Unlike in traditional fire fighting using water, the region that burned is dry and relatively undisturbed but for what has actually been burned after it is extinguished with liquid nitrogen.

Turning now to FIG. 4, another aspect of the present invention is shown, wherein another embodiment of the present invention is used to extinguish and control a house fire. Here, a wind pole 32 is inserted into a window of a house that is on fire in order to determine whether the window is in the fire draw. If, when the window is open, the strips 28 point horizontally, then liquid nitrogen may be inserted at that location. In the present embodiment a pan 34 is placed inside at the top of the window. A plurality of spikes or stakes 16 are attached to the half-circular pan 34 and rest on the windowsill 36. The pan 34 further comprises a plurality of holes. Pouring receptacle 38 transports liquid nitrogen from a dewar into the house via the pan 34. The holes in the pan 34 allow the liquid nitrogen that has been poured into pan 34 to shower down to the floor evaporating inside of the window. The gaseous nitrogen expands during evaporation and cooling and is pulled into the fire and will act to extinguish the fire and prevent re-ignition thereof.

FIG. 5 illustrates another embodiment of the present invention, wherein the present invention is used to control and extinguish a fire within a slab building structure or a fire on a floor of a tall building. Here, the trough 10, having a plurality of holes or apertures therein, is positioned in a central hallway with a T-shaped dewar tube 22 supplying liquid nitrogen to the trough 10 from a dewar 20 located elsewhere at a central pouring location. The entry point of the dewar tube 22 is sealed so as to prevent air from entering. The trough 10 is positioned such that the highest point is located at the central pouring location so that gravitation forces will aid in the distribution of the poured liquid nitrogen to the rest of the trough. As the liquid nitrogen flows through the trough 10, the liquid nitrogen, under the force of gravity, will drop through the holes and evaporate as supercooled air during the fall to the surface below. The inert nitrogen gas becomes a cloud filling the volume of the building or floor of a tall building as it leaves the trough 10. An amount of liquid nitrogen sufficient to flood the structure from the floor to the ceiling as it evaporates into nitrogen gas will act to contain and extinguish the fire.

Referring now to FIG. 6 another embodiment of the present invention is illustrated, wherein the present invention is used to control and extinguish a fire in a tall structure 21 such as a silo, tank or tall building. Where access to the fire zone cannot be reached from the interior efficiently, helicopters 24 can insert a trough 10 assembled to have a solid outer trough 11 that is capped at its outer end for the segment extending from the helicopter 24 to the building or other structure 21 and an apertured trough 13 for the section to be within the structure. The trough is secured to the roof or, if available, adjacent structures in such a manner that the outer section 11 is higher than the inserted section 13 insuring that the liquid nitrogen flow enters the building when poured from dewars aboard helicopters 24 into the trough from above. This, like the application shown in FIG. 5, floods the space within the structure with inert nitrogen gas starving the fire of oxygen and cooling the space with its low temperature. As the liquid nitrogen application continues dropping the temperature in the structure, any fuel or other flammable liquid can be solidified, gelled or frozen allowing fire fighters to shovel up the unburned material and place it in containers for removal.

In another embodiment of the present invention illustrated in FIG. 6, a liquid nitrogen dewar 10 feeds an apertured pan 1 held over a fire directly flooding the fire with the evaporated, supercooled nitrogen gas. This cold gas passes through the heat and smoke to flood the fire with inert gas so as to contain the fire.

2. A Second Embodiment of the Present Invention

Referring now to FIGS. 7-10, and in particular, FIGS. 7 a-d, an explosion ordnance clearing device 46 is illustrated wherein a trough 10 having a plurality of apertures or holes 12 therein, such that flowing liquid nitrogen pours through the apertures 12. The trough 10 is placed over an explosive ordnance 40, otherwise known as a mine, such that the poured liquid nitrogen is applied to the mine after dripping through the apertures 12 in the trough 10. The application of the liquid nitrogen to the mine 40 substantially cools the mine so as to render the explosive material contained therein inert for a period of time long enough to safely transport the mine 40 to a nearby detonation chamber. In another embodiment of the present invention, double-sectioned legs 42 having a structural support section 44 are provided on the outside of the clearing device 46. Additionally, an inflatable inner section 48 is provided on the inside of the device 46.

Turning now to FIGS. 8 a-d, the inner leg sections 48 are filled hydraulically with water or oil. As the legs 48 are filled with water, they are expanded so as to extend to an area underneath the mine 40, thus allowing the mine to be lifted from a surface. Referring now specifically to FIG. 10 c, a trough unit 10 is shown comprising a plurality of leg sections 42 that are expanded sliding underneath a mine 40. FIG. 8 d is an illustration of the underside of the clearing device 46 with a plurality of leg sections 42 extending under the mine 40, thus enabling the clearing device 46, trough 10, and mine 40 to be lifted after the mine 40 has been treated with the liquid nitrogen.

Referring now to FIGS. 9 a-d, a mine 40 is cooled by the application of liquid nitrogen to a circular mine-cooling trough 10 comprising a plurality of apertures such that when liquid nitrogen is poured into the trough 10, the liquid nitrogen flows through the apertures encircling the mine 40 with cold, inert gas, thus cooling the mine quickly but gently and preventing the thermal shock of puddled liquid nitrogen in any crevice on the mine surface. As shown here, the application of the liquid nitrogen around the mine will act to cool the mine and the inner legs 44 so that they will freeze, thus enabling removal of the entire unit, including the mine, as one unit.

The next step in the mine 40 transfer process is illustrated in FIG. 10, where the cooled, inert mine 40 is quickly moved safely into a waiting detonation chamber. A lifting device 48 is employed to facilitate the separation of the mine 40 and the trough structure 10 from the surface. Due to the cooling of the un-detonated mine 40 contained in the trough structure 10, it may be safely transported while the mine 40 is retained at a sufficiently cool temperature. A hook unit 48, such as a thermal gloved hand, lifts the frozen leg basket containing the mine 40 by the rim so a shovel, pallet or spatula 54 can be inserted under the structure, which will then lift the mine in the trough structure without disturbing the explosives so that it may be moved to a detonation chamber 56.

3. A Third Embodiment of the Present Invention

Turning now to FIG. 11, a third embodiment of the present invention is illustrated wherein liquid nitrogen is used to freeze detonators for safe removal thereof. A dewar 20 having an outlet 22 formed inside a drill bit sufficiently long enough to effectively probe near the detonator, is used to release the liquid nitrogen at the level of the detonator in order to freeze it and cool the surrounding area in the immediate vicinity to near-liquid nitrogen temperatures. This will freeze any material in a pipe or containment adjacent to the explosives as well making it safer to work. Next, while retaining the explosives at near-liquid nitrogen temperature, the surrounding area is dug out and removed. As shown in FIG. 11, if the explosive is tied to a well pipe 50, a water cutter 52, or similar instrument, may be employed in parallel to cut the explosive loose of the pipe 50. Liquid nitrogen cooling should continue through removing the explosives and lifting them to a place of safe detonation.

Many changes and modifications could be made to the invention without departing from the spirit thereof. The scope of some of these changes can be appreciated by comparing the various embodiments as described above. The scope of the remaining changes will become apparent from the appended claims. 

1. A method of using liquid nitrogen to control a fire comprising the steps of: a. securing liquid nitrogen in a carrier; b. dispensing the liquid nitrogen to a trough, wherein the trough comprises a plurality of apertures; and c. applying liquid nitrogen to the fire as droplets through the plurality of apertures of the trough so as to substantially flood the space with inert gas.
 2. The method according to claim 1, wherein the trough is secured to a surface through the use of a plurality of spikes protruding from a bottom surface of the trough.
 3. The method according to claim 1, wherein the trough encircles the area affected by the fire.
 4. The method according to claim 1, further comprising the step of ensuring that the liquid nitrogen droplets are dispensed from a distance such that the droplets have substantially evaporated prior to reaching the surface.
 5. The method according to claim 1, further comprising the step of encircling the fire with liquid nitrogen just above a draft air intake level of the fire.
 6. A method according to claim 1, wherein a T-shaped pipe is used to dispense the liquid nitrogen from the carrier in order to divert the liquid nitrogen in at least two different directions at the same time.
 7. The method according to claim 1, wherein the trough is leveled such that an end where the liquid nitrogen is poured is substantially higher than other parts of the trough in order to facilitate flow of the liquid nitrogen through the entire trough.
 8. The method according to claim 1, further comprising the step of using a wind pole comprising a plurality of fabric strips to determine a wind input draft height of the fire, wherein the optimum height for the trough is determined by a break point determined by using the wind pole.
 9. The method according to claim 1, wherein a trough, is employed through one of a window and a wall of a large building in order to deliver liquid nitrogen to the trough so the falling liquid nitrogen droplets flood the space inside the building with inert nitrogen gas.
 10. The method according to claim 1, wherein the trough is assembled at a location ahead of the directional travel of a wild land fire such that upon flooding of the trough, the leading edge of the wild land fire is saturated with the liquid nitrogen.
 11. The method according to claim 1, wherein the trough further comprises a solid trough section attached to an apertured trough section, wherein the solid trough section extends from a location exterior to the area affected by the fire and the apertured trough section extends from an edge of the solid trough section to an area inside the area affected by the fire.
 12. The method according to claim 11, wherein the trough can be raised to the height of a tall structure from an area outside of the area affected by the fire and inserted into an open area of a tall structure.
 13. The method according to claim 11, wherein a helicopter is used to raise the trough to a height such that it may be inserted through an opening in a tall structure.
 14. The method according to claim 11, wherein the liquid nitrogen is applied directly to a pan, wherein the pan comprises a plurality of apertures such that the liquid nitrogen rains down over the fire flooding it with inert gas.
 15. A method of removing an explosion ordnance (mine) comprising the steps of: a. securing a trough comprising a plurality of apertures encircling the mine; b. hydraulically inflating with oil or water, leg segments to slide under the mine; c. dispensing liquid nitrogen to the trough such that the liquid nitrogen drips through the apertures of the trough to the space surrounding the mine, wherein the application of liquid nitrogen to the mine renders the mine inert and incapable of detonation and solidifies the fluid in the leg segments; and d. transporting the inert mine and trough to a detonation chamber so that the mine may be safely detonated in a controlled manner.
 16. A method for safely removing buried explosives comprising the steps of: a. supplying a dewar having an outlet formed inside a drill bit for carrying liquid nitrogen; b. probing an area near the explosive with the drill bit; c. flooding the explosive and surrounding area with liquid nitrogen so as to render the explosive inert; d. removing the surrounding soil and explosive; and e. transporting the explosive to a location for safe detonation.
 17. The method according to claim 16, wherein the step of flooding the surrounding area with liquid nitrogen solidifies the contents of a structure attached to the explosive.
 18. The method according to claim 16, wherein a water cutter is used to cut any strapping holding the explosive to a structure without sparking so that the explosive may be safely removed without damaging the structure. 